Circuit-breaker.



PATENTED FEB. 19, 1907.

F. O. HARTMAN.

CIRCUIT BREAKER.

APPLICATION FILED FEB. 25, 1904.

4 SHEETSSHEET 1.

Wilt names PATENTED FEB. 19, 1907. F. 0. HARTMAN.

CIRCUIT BREAKER.

APPLICATION FILED T13R25, 1904.

4 SHEETS-SHEET 2.

Witwooaeo Waifi No. 844,353. PATENTED FEB. 19, 1907. F. O. HARTMAN.

CIRCUIT BREAKER.

APPLICATION FILED FEB.25,1904.

4 SHEETSSHEBT 3.

w W m No. 844,353. PATENTBD FEB.19, 1907. P. 0. HARTMAN.

CIRCUIT BREAKER.

APPLICATION FILED FEB. 25, 1904.

4 SHEETS-SHEET 4.

UNITED STATES PATENT OFFICE.

FRANK O. HARTMAN, OF MANSFIELD, OHIO CIRCUIT-BREAKER.

Specification of Letters Patent. Application filed February 25, 1904. Serial No. 195,225.

Patented Feb. 19, 1907.

. new and useful I-m rovements in ircuit-,

ticularly for the protection 0 Breakers, of which t e following is a specification. 1

circuit-breakers, and has particular reference to that class of circuit-breakers. wherein is Erovided means for automatically opening or reaking an electric circuit upon the occur rence of a predetermined flow of current and my present invention is designed more parhigh-potential circuits.

The objects of in improvement are, first, to

provide a means or automaticallyopening or breakin an electric circuit upon the occurrence 0 an overloador a'short circuit in' combination with a means in the same device for opening the circuit by hand, thereby dispensmg with the necessity for providing an additional hand-switch inthe circuit when it is desired to break the current manually; second, tq prevent the resetting of the switch when an overload exists and to insure the automatic and instantaneous opening of the switch when such conditions prevail irreslpective of the fact that the operating-hanle remains in the gras of the operator; third, to provide a means or utilizing the current flowing from the high-potential circuit to operate the tripping mechanism, as well as providing means for insulating the operating mechanism and frame therefrom.

A further object of my invention is to construct a circuit-breaker insuch a manner as to leave the movable laminated contacts and stationary terminals immersed in an insulating liquid whereby arcing is reduced to a minimum when the circuit is broken from any cause.

A speial feature of my invention is in the means shown for operating and controlling the laminated bridging contacts and in bringing them in and out of engagement with the stationary terminals, the construction of my devicefbeingsuch that the laminated bridging contacts. reciprocate vertically and in diyrect alinement at all times with the stationary terminals. l

An important feature ofmy lnvention is the facility afforded in its construction for instantaneously breaking the circuit in case of an overload or current on the circuit in excess of'a predetermined amount when the operator is in the act ofclosing the circuit through the medium of the operating-handle and clutch preparatory, to locking the lami. nated bridging contacts in closed position.

I attain these and 'otherobjects by the mechanism illustrated in the accompanying My invention relates to improvements in f drawings, in which Figure 1 is a view in perspective looking from the rear showing the circuit-breaker in open (position, one of the casings be' remove Fig. 2 is a similar view taken om the front, showin the circuihbreaker in closed" position; 'Flg. 3 is a view in vertical cross-section showing the locking mechanism and trip. Fig. 4 is a detail view, partly in section, of the locking mechanism and clutch; and Fig."5 is a view in vertical crosssection taken on a line at right angles to Fig.

3, showing the laminated contacts, the trip, and locking mechanism. In constructing my device I provide asuitably-supported bracket 1, from which pro-' {)ects a table 2 at an angle therefrom, the ta- 1e being rovided on two opposite sides with a series oi number of contacts or terminals employed, the apertures being countersunk, as at 3 and adapted to receive tubular bushings 2 2 of some suitable insulating material, the bushings each provided with a circular groove 3 designed to receive a leaden ring 3, the size of which ring is such that a portion thereof'rests in the countersunk recess 3,

surrounding the aperture 2*. A locking annulus 4 snugly fits around each bushing, the annuli each provided with a groove 5, formed therein'to engagethe exposed portions of the; rings 3 3. Each annulus isfastened to the table by suitable means, as the screws 6, whereby to firmly engage the rings 33 and retain the bushings 2 rigidly in position.

Depending from the table are a plurality "of rectangular casings 63 63, corresponding with the number of'movable contacts emapertures 2 2*, according to the y ployed, the casings preferably extending" transversely across'the table and consisting of a metallicboX lined with a suitable non conducting material, as'shown at 64. Ribs, 65 are removably secured to the table,

upper edges of the casings being securedt'o the ribs in any convenient manner.

The bushings are of such length as to prorro ject some distance above and below the surfaces of the'table 2, the bushings depending into the casings, each casing adapted to inclose two bushings, one on each side of the table. The casings are each filled with oil into the oil or other fluid in the casings and conducting material.

are provided at their lower ends with cushioning-sleeves 66 66, of wood or other non- Passing through each bushing and its attached sleeve is a stationary contact member 7 the upper POI'LlOIl of which is threaded to receive a nut 8, seated in a recess 60, formed in the upper end of the bushing, the nut being .cushioned by means of a packing 67 and operating'to sustain the contact member relative to the bushing. The threaded ends of the contact members project some distance above the bushings for a purpose hereinafter set forth, and their lower ends terminate in enlarged feet 68, lying adjacent the sleeves, 66, which feet are. engaged by the movable contact members, as presently to be described. The feet are each provided with an extension 69, removably secured thereto in an conven ient manner, as shown, these bloc s 69, be ing the last points engaged by the movable contacts when the circuit is being broken and being removable, so that in case they become burned by arcing new blocks can be easily and quickly substituted therefor at a minimum cost, thus avoiding the necessity minal.

brass.

Each case 63 contains a pair of stationary terminals spaced apart from each other.

The blocks are preferably formed of Inserted in the table 2 at apoint preferably mi way between the stationary terminals is an apertured bearing-block 30, of' wood,

which is removably secured to the table in any'suitable manner. A rod 29, of wood or other non-conduct1ng material, passes through the aperture in the block, the block being of some depth to afford a bearing for the rod and prevent lateral play thereof, the rod bein provided with a shoe 31 at its lower en having a corrugated socket 33, in which the rod is received, a pin 32 passing through both rodand socket to secure the shoe to the rod. The lower face of the shoe 5 is oppositely-inclined, as shown, and is provided with a holder 35, laminated bridging contacts 34 34 being received between the .holder and shoe and the whole being removably secured by fastening means 36 to the shoe. The ends of the laminated sheets 34 34 enga e the feet 68 of the stationary terminals in t e usual manner, one of the elite rior sheets being elongated and provided with a removable contact-block for engagement with the block 69 to reduce the point -of engagement between the stationary and movable contact member s, whereby the liability of arcing when the circuit is broken is reduced to a minimum.

The rod 29 is adapted .to reciprocate through the bearing-block 30, the rod being of sufficient length so that the movable bridge-contact at its lower end is always submerged in the liquid in the casing.

A cross-head 27 extends transversely of and above the table 2, the cross-head having threaded apertures 71, in which the upper ends of the rods 29 29 are received and secured. This cross-head is also provided with hollow bosses 28, the upper ends of which removably receive adjustable caps 72, to which are secured the springs 73, the opposite ends of the springs being secured to the nuts 74, removably secured to the table 2,

the hollowbosses forming casings in which the springs are received when the circuit is broken-and the bridge-contacts lieintheir lowermost positions, as shown in the dotted lines 37 37 in Figs. 3 and 5. is furthermore provided with lugs 38 38, in which is journaled a pin 39.

Suitably journaled in the bearing 61 of the bracket 1 of the frame is the rod 42, it being prevented from endwise movement by the removable screw 75. The inner'end of the rod has secured thereto the crank-disk 44, a stud 45 passing through the rod and crank-disk to prevent the rotation of the disk relative to the rod. A link 46 is pivotally secured at one end to the disk '44 and eccentrically thereof by means of a stud 47, the op osite end of the link being pivotally secure to a shackle 48, to which shackle is pivotally secured a lever 50, one end of the lever being journaled upon a stud51, located in a slot 62 iii the bracket 1, and its opposite bifurcated end embraces the shank 41 of a book 40, the shank being pivotally secured intermediate its ends to the bifurcated end by means of a stud 53. A leaf spring 56 is secured to the hook at one end, the opposite end of the spring engaging the lever 50, whereby to prevent the 'movement of the hooked end ofthe shank toward the lever from a position at substantially right angles thereto. The upper projecting end of theshankhas secured thereto an upturned arm 54, lying above the lever 50, to which-lever is securedffilleaf 'tion between the rod 42 and t e lever 50.

The outer end of the rod has rigidly secured thereto a clutch-collar 57, having the projec- The cross-head tion 57, and a corres onding clutch member 58 is loosely journale on the shaft, the latter member provided with a projection 58,

adapted to en age the projection 57 whereby to rotate t e shaft and through the me? dium of the crank-disk, link, and'shackle to draw the lever 50 and the hook 40 down, so

that the hook will engage the roller or pin 39 I upon, the completion of a semirotation of the rod 42, the reverse rotation of the rod then operating to "raise the bridge-contacts into I 73 73. being enga ement with the stationary terminals and c 'ose the circuit. The clutch member 58 is provided with a suitable handle 59, where by to rotate the rod,'ianda stop 76 is located outward and releasing the cross-head, which at once descends, owing to the tension of the springs 73 73, and by reason of its weight or the shaft 42 maybe rotated, which will pull down the lever 50, thus lowering the hook 41 and permitting the springs 7 3 73 to force the cross-head and the bridge-contacts away from. the stationa terminals. The hook 40 is inclined, as s own, whereby to slide over the pin 39, the spring 56 always preventing the hook-from riding in front of the in and the spring causing the hook to catc under the in. I I A supportingar 9 is received upon the projecting end of one of each pair of stationary terminals, a jam-nut 10 being placed above the bar on the terminal 7 to retaidthe bar in place. -The bars 9 9 project parallel with and laterally of thetable and are adapt ed to sup ort the solenoid-coils 11, each ofwhich coi s has a'centrally-disposed longitudinally-extending tube- 12 received therein and extending below and above the coil,- the tube being 0 an at its upper end and lined with a suita'bldfiber 77 art way of its length. In the lower portion 0 the tube is secured a second tube'7 8, threaded at its lower end for the reception of ;'a nut 79, having a threaded aperture extending therethrough, wherein is received the ad usting-screw 17, upon the u per end of which rests a core 16, movab e within the tube and adjustable therein by means of the screw 17. The lower ends of the coils are seated in the bar 9, their up or 7 ends being received in a' plate 14, which atter is provided with abinding-post 80 at its outer end, the plate being suitably secured by means of a bolt 81 extending between the supporting-bar 9-and the plate 14, the bolt bei insulated from each by means of the thirn les 82 and being inclosed .within the hollow standard 13, which latter is formed of.

' The upper end of the tube 12 projects through the plate 14 and is provided withan apertured cap 15, in which is loosely received the double-headed releasing-pin 18.

.A standard 24, projectin from the bracket 1, supports the orizonta ly-extendingrod 26, which supports a hanger 25, and journaled in the hanger and in the standardis a shaft 23, the shaft adapted to have the sleeves 83' adjustably secured thereto, thecollars each provided a socket 21, in which is received and secured one end of an inclined rod 20 of suitable insulating material, the opposite or free ends of the rodcarrying the frusto- I conically-shaped collars 19, adjustably secured thereon. The collars rest on theupper. ends 'ofthe releasing-pinslS and are conical inorder that a good full contact may be made with the pins in view of the nclined positions of the rods 20. Secured upon the shaft 23 is a trip 22, projecting ina dlrection opposite to that taken by the rods 20,- the trip extendin over and in close proximity to the arm 54 w on the latter is in its normally raised position, as when the bridging con-- tacts are being held in engagementwith the stationary terminals.

The current enters through the plate. 14,

whence it passes through the solenoid to the.

supporting conducting-bar 9, thence to thestationary terminal. 7, with which conductor 9 is connected, thence across the laminated bridge-contact to the'opposite stationary terminal, from-whence it is taken by means of.

the insulated wire 84, removably secured to the projecting threaded end of the stationary terminal by means of the coupling 8'5.

When several bridge-contacts are used, as

in ract-ice, I provide 'ashield 86 of a'nysuitabla non-conducting material or fiber, which isfsecured to one edge of the table and extends therealong to protect the depending "portions of the solenoid-tubes 12 and prevent contact therewith, since the depending portions are live, and to separate them from the frame of the apparatus. Furthermore, Iprovide a casing 87, formed of laminated sheets'of, insulating material, in'which'ca'se are mounted the solenoids, and between each two of'solenoidcoils is located an insulatingplate 89 to separate the COIlS.

I The bracket 1 is'provided with a plurality of a erftures .88 to admit of the attachment of't e circuit bre'ak'er to the s' witchboard. (Not shown.) Y

From the foregoing it will be observed that the handle is turned in one d1rection say toward the right-to lower the lever 50 and cause the hook- 40 of the catch 41 to engage the pin 39 on the cross-head, the handle and the rod thenbeing rotated in the o posite direction to raise the cross-head an 'l'ami nated bridge-contacts, since a further move- -ment of the crank 44 toward the right 1s some suitable non-conducting materiaL.

prevented by the stop 76; but by reason of the fact that there is but one tooth 57 and 58 on each of the clutch members the han dle will loosely rotate on rod 42 until its tooth once more engages the tooth on the fast member of the clutch, whereupon a hall-rotation to the left will straighten the toggle, thereby raising the lever 5'0 and the cross-head until the laminated contacts are pressed tightly against the stationary terio..mi11itlS and the springs 73 extended. As

heretofore set forth, the circuit can be manually broken by reversin the rotary move-- ment of the handle, whic will of course depress the lever. In the event of an overload 15 on the circuit, however, when the laminated contacts are in their raisedposition the increased current entering the solenoid attracts the loose core 16 in the usual manner and causes it to impinge smartly against the zo iower head of the releasing-pin 18, which 11 turn imparts an pscillat ory movement to the shaft- 23 through the medium of the rod, 20, thereby causing the trip-arm 22 to engage and depress the arm 54 and rock the catch 25 41 on its pivot 53' and against the tension or spring 55, whereby to release the in 39 and I permit the instant breaking of t e circuit. In this connection it will be noted that the arm 54 and the catch 41 constitute, in effeet. a bell-crank. The stop 7 6 is so located that the toggle-joint formed by the link 46-, shackle 48, and disk 44 passes slight y beyond its dead-center when inextended position, the disk resting against the stop, which 5 thus operates to prevent any slight jar or other inadvertent movement from opening the circuit by breaking the toggle, since as soon as the toggle is broken the tension oi springs 7 3, as well as the weight of the bridg- 4o ing-contact members, will force the latter away from the stationary terminals. The springs insure a quick break upon the occurrence of an overload and counteract any tendency of the movable contacts to stick or 45 freeze, and the tension oi the laminated sheets assists this movement, In the event that the operator endeavors to close the circult during the continuance of an overload the following operation will take place: The

lever 50 being in its upright posii ion, the operating-rod 42 is rotated toward the right to lower the lever and its catch 41, so that the hook 40, carried thereby, may engage the cross head. The rod is then rotated in the opposite direction until the laminated bridge member is brought into contact with the stationary terminals, whereupon the circnit is completed and the electroresponsive mechanism energized to cause the partial ro tation of the shaft 23 and its trip 22-, the tter being brought down upon the arm a the catch to cause its release from its ere head and permit the latter to descenrjl to break the circuit while the handle 59 la mains in the grasp of the operator. Thus itsenses will be seen that it isimpossible to close or complete the circuit during thecontinuance of an overload.

As will be observed, the drawings disclose a mechanism known as a three-pole circult-breaker; but it is plain that it can be constructed in single, two-pole, or four-pole combination or more by using a lesser or greater number of units. It is further obvious that many changbs might be made in the form and arrangement of the a several parts described without departing from the spirit and scope of my invention, and hence I do not Wish to limit myself to the exact construction herein set forth; but,

Having fully described my invention,what I claim as new, and desire to secure by Letters Patent, is-

1. The combination with a circuit-breaker,

a plurality of stationary terminals, a movable bridge-contact adapted to engage the terminals and a supporting means secured to the bridge, a rod and lever, a toggle connecting the rod and lever, and acatch on one end of the lever for holding the bridge in contact with the terminals.

2. The combination with a circuit-breaker, a lurality of stationary terminals, a movab e bridge-contact adapted to engage the terminals and a supporting means secured to the bridge, a rod and lever, a toggle conne'ct ing the rod and lever, a catch on one end of the lever for holding the bridge'in contact with the terminals and means on the rod for operating the catch.

A circuit-breaker comprising a plurality of stationary terminals, a bridgecontact for engaging and connecting the terminals, a supporting member to which the bridge-contact is secured, a 'manually-operable rotatable rod independent of and removed from the bridge contact supporting member, a suitably-supported lever, a toggle connecting the rod and lever and a catch on the lever for releasably engaging the supporting member.

4. A circuit-breaker comprising a plurality of stationary terminals, a bridge-contact for connecting the terminals, a supporting member to which the bridge-contact is secured, a rotatable manually-operable shaft, a suitably-supported lever ocated apart from the sup ortingmemh 3 a toggle connecting the shatt and'lever, a stop for limiting the movement or the shaft in one direction and a catch adapted to releasably engage the con tact-supporting member.

5. A circuit-breaker comprising stationary terminals, a bridge-contact connecting the terminals, a supporting member to which the bridge-contact is secured, a rota manuallyoperable shaft, a crank secure thereto, a link loosely secured to the crank, a shackle loosely secured to the link, a pivotally-supported lever releasably connected to the contact-supporting member to which the shackle is also loosely secured,,and a catch carried by the lever and releasably engaging the contact-supporting member.

6. The combination of a plurality of electric switches, each switch consisting of separated terminals, and a bridging memberfor engaging said terminals, a horizontally-journa e rotatable operating-arm, a lever, a toggle connecting the arm and lever, means on the lever for engaging the bridge, bringing it in contact with the *terminals, and means for releasing said bridge automatically upon supporting member, means for oscillating the lever comprising a means for locking the lever in one position, a catch pivotall secured to the lever and adapted to releasab y engage the su porting member to temporarily connect tiie lever and sup orting member, an arm carried by the catch and electroresponsive means for causing the release of; the catch from the sup orting member. 8. A circuit-brea er comprising stationary terminals, a bridge-contact removably engagin the terminals, a supporting member to Which the brid e-contact is secured, a rotary rod, a pivota ly-su ported lever, means connecting the rod and ever, a catch releasably engaging the su porting member, a handle loosely mounted on the rod and cooperating clutch members carried by the handle and rod res ectively.

-9. In a circuitreaker, the combination with a stationary terminal, of a su porting bar, mounted upon and in' electrica conneca tion with the terminal, a connecting-plate and an electroresponsive means connected between andelectrically connecting the connect' -plate and supporting-bar.

10. n a lcircuit-breaker, the combination with a stationary terminal, of a su porting,- bar mounted upon and in electrica connection with the terminal ,a iconnectiniglate, an electroresponsive device locate etween and electrically connectin the-connectingplate and the supportingar, and an insui l. l s

, ated brace extend ng between and mechanically connecting the connecting-plate and supporting-bar. I I

11. In a'circuit-breaker, the combination with a stationary terminal, of a sup ortingbar secured thereto andproject'ing literally therefrom, a 'connectingplate, an electrores onsive device secured between the bar and plate, insulating-sleeves passingthrough the bar and plate and a brace received within the sleevesand connecting the bar and'plate.

12. a circuit-breaker, the combination hanger carried mounted in the anger, a rod adjustably sewith a stationary terminal, of a supportingbar secured to the terminal, a connectingplate, a solenoid-coil located between the connecting-plate and supporting-bar, a fiberlined tube in and forming a part of the solen- 01d, the tube depending some distance beneath the solenoid-coil, a core adjustably located within the tube, a suitably-supported rotary shaft, a rod carried by and prqecting from the shaft, an arm also carried by the shaft, the rodextending to a point adjacent the solenoid, a'pin engaged by the core for actuating the rod, a movable bridge-piece, means for raising and retaining the bridgeplece in contact, with the stationary terminal and an arm on the last-named means, the lastnamed arm adaptedto be engaged by the arm on the shaft for releasing the en agement of said means and the movable bri ge-piece.

13. In a circuit-breaker, the combination with stationary electrodes, a bridge-contact for connecting the electrodes-and means for brin ing the contact into engagement-with the e ectrodes, of a connecting-bar secured to mounted on the shaft and extending to a point adjacent the solenoid whereby it is actuated, a member also carried by the shaft adapted to impinge against the contact-actuating means for releasing the contact from the means. v a

'14. in a circuitibreaker, the combination with a frame, of stationary terminals, as bridge-contact adapted to connect the terminals and means'releasabl connected with and independent of the bri ge-contact member for'bringin it into engagement with the terminals, aso enoid connected with one of the ter1ninals, insulating means located between the solenoidand the circuit-breaker frame, asuitabl supported stationary bar, a the bar, a rotatable shaft cured to the shaft, electrically operated means for actuatin the shaft, and an arm actuated by the sha t for impingi the contact-actuating means and causing t e release of the bridge-contact therefrom.

15. The combination in a multi olar circuit-breaker, with a single table, 0 'a plurality of independent casings, stationary terminals supported by the table, their lower ends received in the casings, a bridge-contact in each of the casings for connecting the terminals, a series of solenoids 'connectedwith forconnecting each of the solenoids to a circuit, insulating-plates located between each two adjacent solenoids, a casi in which the solenoids are mounted, releasa le manuallyoperated means for bringing the contactsinto engagement with the stationary terminals certain of the stationary terminals, means and means actuated by the cores of the solenoids'for releasing the bridgecontact from I its manually-actuated engaging means.

16. In a circuit-breaker, the combination with a lurality of stationary terminals, of a movab e bridge-contact for connecting the terminals, a lever, means carried b the lever for releasably engaging the movabih contact, manually-operated means connected with the lever and actuating the latter to cause the bar secured thereto. and projecting lateral therefrom a connecting-plate, an elect'rors onsive device secured between the bdr and ate, insulating-sleeves passing through the it! and plate and a brace received within the sleeves and connecting the bar and plate. 1 8. The combination of a plurality of electric switches, each consisting of separated terminals and a bridging member for engaging said terminals, a horizontally-position'ed rotatable operating-arm journaled in the frame of the circuit-breakerfor bringing said bridgin members into engagement with the terminefs, a toggle for locking said bridgirigg members in such position, and means for e ecting the automatic and simultaneous release of said movable contacts and positively and actually disconnecting the same from the operating-arm upon the occurrence of an overload.

19. 'An electric switch consisting of movable and stationary contacts, a horizontallyp'ositio'ned rotatable operating-arm journaled in the frame of the circuit-breaker for bringing said movable contacts into engagement with said stationary contacts, a pivotallysupported lever located apart from the operating-arm, a toggle connecting the arm and lever and locking said switches in normal position, and one or more solenoids operating to release and absolutely disconnect said movable contacts from said operating-arm upon the occurrence of an overload on the line, and preventing the c'iosing of said switches, while such overload exists.

20. The combination'of a plurality of electric switches, each switch consisting of separated terminals, and a bridging member for engaging said terminals, a horizontally-positioned. rotatable operating-arm journaled in the carrying-frame of the circuit-breaker, a single means connected with the operating arm and temporarily engaging the bridging member for bringing said bridging member into engagement with the terminals, a toggle constituting a portion of the connecting means for locking said bridging members in such position, and one or more solenoids mounted on the carrying-frame of the circuitbreakers, energized by current from the highpotential circuit and operating to absolutely release the engagement of the bridging members with the connecting means upon the occurrence of an overload.

21. The combination of a plurality of electric switches, each switch consisting of separated terminals and a movable member for engaging said terminals, a rotatable operating-arm journaled horizontally in the carryving-frame of the circuit-breaker for bringing said movable members into engagement with the terminals, apivotally supported lever located apart from the operating-arm, a toggle permanently connectingthe operatingarm and lever for locking said movable members in closed position, means releasably connecting the lever and movable members,

means for absolutely disconnecting said movable members automatically from the lever upon the occurrence of a predetermined overload, and means for manually releasing said movable contacts and permitting the unrestricted movement of said movable members by turning said operating-arm in thedirection opposite to that taken in closing the switch.

22. The combination of a plurality of electric switches, each switch consisting of separated terminals, and a bridging member for engaging such terminals, a horizontally- ;ournaled rotatable operating-arm, a lever ocated apart from the operating-arm, a toggle permanently connecting the lever and arm, said arm operated for bringing the bridging member into engagement with the termivnals and locking them in such position,

means carried by the lever for releasably connecting the lever with the bridging member, and one or more solenoids mounted on insulators in electrical contact with one of the terminals of each switch, said solenoids operating collectively or separately for releasing the bridging contacts upon the occurrence of an overload.

.23. An electric switch consistingof separable contacts to open and close the circuit, a toggle for locking the movable member of such switch in normal position, means for absolutely disconnecting said movable member automatically from its operating means upon the occurrence of a predetermined overload, and means for absolutely disconnecting said movable member manually from its operating means.

24. In a circuit-breaker, the combination with a plurality of stationary terminals and a bridging contact movable toward and from the terminals, of a rotatable manually opcn from the shaft, a link connecting the lever,

ated shaft, a lever pivoted at a point distant contact movable toward and from the terminals, of a catch for releasably engaging the bridge-contact, manually operating mechanism to which the catch is pivotally secured for moving the catch into engagement the bridging contact when the latter is in its position removed from the terminals, to move the bridge into engagement with the term1- nals, and electroresponsive means, a rod, a shaft, said rod connected to the shaft, and a trip mounted on the shaft adapted to engage the catch to cause it torelease the bridging contact irrespective of the operating means. Signed at Mansfield, Ohio, this 15th day of January, 1904.

FRANK O. HARTMANl Witnesses:

R. W. HARTMAN, ANNA HARTMANN. 

